Isotopes and Calculating Atomic Mass

What is the formula to calculate average atomic mass?

• Average Atomic Mass = (mass of isotope 1 × percent abundance of isotope 1) + (mass of isotope 2 × percent abundance of isotope 2) + ...

• Average Atomic Mass = (mass of isotope 1 + mass of isotope 2) / 2

• Average Atomic Mass = (mass of isotope 1 × mass of isotope 2) / (percent abundance of isotope 1 + percent abundance of isotope 2)

• Average Atomic Mass = (mass of isotope 1 + percent abundance of isotope 1) - (mass of isotope 2 + percent abundance of isotope 2)

How do you determine the number of neutrons in an isotope?

• Number of neutrons = Mass number - Atomic number.

• Number of neutrons = Atomic number + Mass number.

• Number of neutrons = Mass number / Atomic number.

• Number of neutrons = Mass number - 2 x Atomic number.

What is the average atomic mass of an element with 4.35% of atoms at 39.946 amu, 83.79% at 41.941 amu, 9.50% at 42.941 amu, and 2.36% at 43.939 amu?

• 41.97 amu

• 40.12 amu

• 42.00 amu

• 39.50 amu

What is the relationship between atomic number and mass number?

• The mass number is the sum of protons and neutrons in the nucleus, while the atomic number is just the number of protons.

• The atomic number is the sum of protons and neutrons, while the mass number is just the number of protons.

• The mass number is equal to the atomic number multiplied by two.

• The atomic number and mass number are the same and represent the total number of particles in the nucleus.

What is the significance of neutrons in isotopes?

• Neutrons contribute to the mass of an atom and can affect the stability of the nucleus.

• Neutrons determine the chemical properties of an element.

• Neutrons are responsible for the color of the atom.

• Neutrons have no effect on the mass of an atom.

What is the atomic number of an element?

• The number of neutrons in the nucleus of an atom.

• The number of protons in the nucleus of an atom, which determines the element's identity.

• The total number of electrons in an atom.

• The mass of an atom measured in atomic mass units.

How do isotopes differ from each other?

• They differ in their number of protons.

• They differ in their number of electrons.

• They differ in their number of neutrons and therefore have different atomic masses.

• They differ in their chemical reactivity.

What is percent abundance in relation to isotopes?

• The total number of isotopes present in a sample.

• The average mass of all isotopes of an element.

• The relative amount of each isotope of an element in a sample, expressed as a percentage.

• The percentage of isotopes that are radioactive.

What do isotopes of an element have in common?

• They have the same atomic number and electrons.

• They have different atomic numbers but the same mass number.

• They have the same number of neutrons but different electrons.

• They have different chemical properties but the same atomic mass.

What is an isotope?

• Atoms of different elements with the same number of neutrons.

• Atoms of the same element with the same number of protons but different numbers of neutrons.

• Atoms that have the same mass number but different atomic numbers.

• Atoms that are chemically identical but have different electron configurations.